Manufacture of flexible metallic tubes and the like



A. DREYER April 5 1932.

MANUFACTURE OF FLEXIBLE METALLIC TQBES AND THE LIKE Filed March 19, 1931 Patented Apr. 5, 1932 ALBERT DREYER, OF LUCERN'E, SWITZERLAND MANUFACTURE OF FLEXIBLE METALLIC TUBES AND THE LEE Application filed March 19, 1931, Serial No. 523,870, and in Germany November 16, 1929.

The manufacture of flexible metallic tubes or corrugated tubes by rounding an iron band, welding the longitudinal seam of the tube and shaping the tube wall so as to form 6 ridges or grooves extending parallel to one another or along a helical line could hitherto be carried out to'a width of at the most 75 mm, as hand iron of more than about 340 mm. width could not be obtained commercially.

10 Thus, for instance, for producing a corrugated tube of 75 mm. internal diameter as the blank, tubes of about 100 mm. internal diameter are required. In order to be able to produce such a tube a band having a width of about 315 mm. is already required. Considerably greater internal diameters can therefore no longer be made even if certain foreign rolling mills should eventually be able toproduce bands of up to about 4.50 mm. width, which would certainly represent the maximum width capable of being produced. Even then in the most favourable case it would be possibleto produce a tube diameter of about 150 mm. or a tube having an internal diameter of about 115420 mm., which would not represent any considerable impr ovement over what has beenmanufactu-red hitherto. It is, however, desirable to produce flexible tubes up to at least 300 mm. internal diameter and even if possible larger tubes, as, more particularly for crude oil, petrol and the'like, flexible tubes up to 250 mm. internal diameter are required.

The method of producing flexible metallic tubes or corrugated tubes forming the subject matter of the present invention again makes use of band iron, in which the band iron is in the first place mounted in a known manner transversely to its longitudinal-direction to form a tube, whereupon the longitudinal seam is closed by butt-welding, the tube being then calibrated and finally the wall of the tube shaped into grooves lying parallel nextto one another or extending helically.

The essential feature of the invention is that, for forming the tube, a band is used which consists of separate bands united along their longitudinal edges by butt-welding so 60 that bands of any desired width are obtained drawings, which represents a constructional 4 example diagrammatically, three separate iron bands a a a of ordinary commercial width are in the first place converted by uniting their longitudinal edges .9 by autogenous or electric butt-welding'into a band A of suitable width. This band A is then converted in accordance with Fig. 2, by means of a suitable rounding device (rounding channel, profiled rolls) which becomes operative at 1, into the form of a tube B with the seam b, after which it is preliminarily calibrated or sized at 2 (for instance by means of a draw-plate), the seam is welded at 3 (for instance by means of a welding burner) and finally calibrated or shaped to its finished size at 4 (for instance by means of three pairs of rolls, disposed one behind the other), thus providing the finished tube 13, ready for be- 4 ing further dealt with, as already more particularly described in British Patent 294,598. (or my American Patent application, Serial No. 217,985 of February 29, 192 8) The tube can then be made flexible by shaping the tube walls into ridges 0 or grooves a, lying par-' allel to oneanother as shown in Fig. 3, or by shaping the walls into helically extending ridges d or grooves d", as shown in Fig. 4, which-may be done by any of the known processes.

What I claim is: l. A method of producing metallic flexible tubes and corrugated tubes of band iron, consisting in butt-welding a plurality of separate bands together along their longitudinal edges to form a single band, rounding the i band thus obtained transversely to its longitudinal direction to form a tube, closing the seam of the tube by butt-welding, calibrating the tube to its final dimension and shaping the tube walls into grooves lying parallel 5 next to one another around the tube, as and for the purpose set forth.

2. A method of producing metallic flexible tubes and corrugated tubes of band iron, consistin in butt-welding a plurality of sep- 10 arate iands together along their longitudinal edges to form a single band, rounding the band thus obtained transversely to its longitudinal direction to form a tube, closin the seam of the tube b butt-welding, cali rating the tube to its fizial dimension and shapingl the tube walls into grooves extending he 'cally around the tube, as and for the purpose set forth.

In testimony whereof I aifix my signature ALBERT DREYER. 

